\contentsline {chapter}{\numberline {1}Prologue}{7}
\contentsline {section}{\numberline {1.1}Important note - Other works}{7}
\contentsline {chapter}{\numberline {2}Theoretical Principles}{8}
\contentsline {section}{\numberline {2.1}Solving multiple user problem}{8}
\contentsline {section}{\numberline {2.2}RSA in theory}{10}
\contentsline {section}{\numberline {2.3}Theoretical solution of the trust problem}{10}
\contentsline {subsection}{\numberline {2.3.1}Technical notes about QR-Codes}{12}
\contentsline {section}{\numberline {2.4}Attack vectors against the system}{13}
\contentsline {subsection}{\numberline {2.4.1}Private key has been stolen}{14}
\contentsline {subsection}{\numberline {2.4.2}Username and password are stolen}{14}
\contentsline {subsection}{\numberline {2.4.3}Smartphone is stolen}{14}
\contentsline {subsection}{\numberline {2.4.4}Programming errors - direct access to the database}{14}
\contentsline {subsection}{\numberline {2.4.5}Hijacked Terminal}{15}
\contentsline {chapter}{\numberline {3}Implementation of the Server Component}{16}
\contentsline {section}{\numberline {3.1}Used Technologies}{16}
\contentsline {subsection}{\numberline {3.1.1}Spring IoC}{16}
\contentsline {subsection}{\numberline {3.1.2}Hades}{17}
\contentsline {subsection}{\numberline {3.1.3}Maven}{17}
\contentsline {subsection}{\numberline {3.1.4}Communication Protocol}{18}
\contentsline {section}{\numberline {3.2}Architecture}{19}
\contentsline {subsection}{\numberline {3.2.1}Domain Model}{19}
\contentsline {subsection}{\numberline {3.2.2}Transfer Domain Model}{20}
\contentsline {subsection}{\numberline {3.2.3}Service Overview}{22}
\contentsline {subsection}{\numberline {3.2.4}Analysis}{22}
\contentsline {subsection}{\numberline {3.2.5}Concrete Services}{22}
\contentsline {section}{\numberline {3.3}Problems and Specialities}{23}
\contentsline {chapter}{\numberline {4}Browser frontend}{24}
\contentsline {section}{\numberline {4.1}Used technologies}{24}
\contentsline {subsection}{\numberline {4.1.1}Encryption/Decryption}{24}
\contentsline {subsection}{\numberline {4.1.2}Views}{25}
\contentsline {subsection}{\numberline {4.1.3}Creating Barcodes}{25}
\contentsline {section}{\numberline {4.2}Layout}{26}
\contentsline {section}{\numberline {4.3}Problems and Specialities}{27}
\contentsline {chapter}{\numberline {5}Retroperspective}{28}
